they take a look at a number of case studies, each one of bush as an illustration of where the united states has been deliberately develop weapons that are designed to be less powerful, less sadly, less destructive than the kinds of weapons they are designed to replace. >> host: what is one of those weapon systems today? >> guest: the first dose duration and easiest to grasp is the precision guided emissions. the oldest of the case studies as an illustration of where by making weapons much more accurate, much more accurate than they've been previously run against the user a great deal of military advantages. you can be more precise. you can make sure you heard only the target they're aiming at and they use fewer weapons to do less damages. that makes that more deaths, more precise, more useful in combat. >> host: was the neutron on going in that direction in a sense? and custodial illustration of the second of the case are these, which is nuclear weapons, but in particular low yield weapons in the arsenal of the superpowers over the years of the cold war have been so large, so distrac